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Connor McDonald

Thanks for the question, Gaurav.

Asked: September 15, 2017 - 7:06 am UTC

Last updated: May 11, 2018 - 5:41 am UTC

Version: 12.1.0.2

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You Asked

Hi Tom

I have active data guard setup for my CDB . It means i have physical standby CDB (with multiple pdbs) . I know replication and database_Role are at CDB level and not pdb level . I have a PDB from different application . Initially when we start with migrating non-cdb to CDB as PDB we did not realize what would be our approach for replication . Down the line when 6 PDB got migrated from non-cdb to pdb a requirement of physical standby came in picture and we setup a physical standby at CDB level . It means all my PDB are getting replicated now

My question is what are best possible options are available for reporting purpose . Some i know i can open as read-only & as snapshot database . Can you please suggest Is any option in CDB is available for reporting purpose where i change / alter option at PDB level and rest other PDB Still get replicated .In other words what is the best strategy to open a standby CDB database as read only / read write

Thanks Tom
Gaurav

and Chris said...

What do you mean by "best"? What exactly is your goal here? What are your requirements and constraints?

For me, the "best" option for standby reporting is Active Data Guard. This enables you to open the databases read-only while the transactions are still applied. But this requires an extra license.

As of 12.2 you can replicate a subset of the PDBs in a CDB as defined by the ENABLED_PDBS_ON_STANDBY parameter:

http://docs.oracle.com/database/122/REFRN/ENABLED_PDBS_ON_STANDBY.htm#BEGIN

If neither of these options are available to you, I recommend reading MOS note 2049127.1. This has a detailed description on how Data Guard and Multitenant interact.

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Comments

Gaurav, September 15, 2017 - 8:13 pm UTC

Hi Chris

I have a CDB1 with PDBs .. PDB1 , PDB2 , PDB3 & PDB4 & CDB1 is getting replicated to CDB2 . In turn PDB1 , PDB2 , PDB3 & PDB4 is getting replicated to CDB2 . PDB1,PDB2,PDB3 & PDB4 supports 4 diffrenent prod application . My question is how do i conduct dr switch over activity with out impact other pdbs in CDB2

Thanks
Gaurav
Chris Saxon
September 18, 2017 - 2:23 pm UTC

You can't switchover a subset of the PDBs. Either it's the whole container or nothing.

As MOS note 2049127.1 says:

Note that all Data Guard role transitions occur at the container database level, i.e. you cannot failover or switchover an individual pluggable database.

Gaurav Sinha, September 18, 2017 - 4:00 pm UTC

Thank You !!

STANDBYS=NONE Vs ENABLED_PDBS_ON_STANDBY

Yossi, May 06, 2018 - 2:32 pm UTC

What is the differences between
STANDBYS=NONE (Doc ID 1916648.1)
and
ENABLED_PDBS_ON_STANDBY parameter ( http://docs.oracle.com/database/122/REFRN/ENABLED_PDBS_ON_STANDBY.htm#BEGIN )
?
Connor McDonald
May 11, 2018 - 5:41 am UTC

STANDBYS=

was there in 12.1, and was not about *avoiding* a pdb on the standby, it was about *deferring* the instantiation of that pdb until a later timr.

ENABLED_PDBS_ON_STANDBY only comes into availability in 12.2, and allows true subsetting of the number of pdb's on the standby.
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